1. Field of the Invention
The present invention relates to a machine for cutting plants including:
a hitching structure intended to be connected to a motor vehicle; PA1 a cutting mechanism extending, during work, transversely to the direction of travel during work (work position) and, during transport, at least substantially in the direction of travel during work (transport position); PA1 a suspension arm connected on the one hand to the hitching structure by means of a first articulation of upward-pointing longitudinal axis and on the other hand to the cutting mechanism by means of a second articulation of longitudinal axis pointing at least substantially in the direction of travel during work when said cutting mechanism is in the work position; PA1 a locking device which in the transport position allows the pivoting of the cutting mechanism about the longitudinal axis of the second articulation to be locked and which includes a connecting member connected on the one hand directly or indirectly to the cutting mechanism and on the other hand to the hitching structure. PA1 allowing, in the work position, a movement of the connecting member with respect to the hitching structure, and PA1 preventing, in the transport position, a movement of the connecting member with respect to the hitching structure. PA1 the connecting member is connected to the hitching structure by means of the connecting means which: PA1 the connecting means connecting the connecting member to the hitching structure includes a fourth articulation having an upward-pointing geometric axis; PA1 in the normal work position (cutting mechanism extending horizontally), the geometric axis of the fourth articulation is at least substantially coincident with the longitudinal axis of the first articulation; such an arrangement makes it possible to pivot the cutting mechanism and the suspension arm from the work position into the transport position or vice versa about the longitudinal axis of the first articulation without altering the relative position of the connecting member with respect to the suspension arm and also without altering the relative position of the cutting mechanism with respect to said suspension arm; in particular, such an arrangement makes it possible to keep the cutting mechanism in a substantially horizontal position in the transport position and this has the advantage, when transporting the cutting machine, of keeping substantially the same ground clearance in the wind rowing position (cutting mechanism extending transversely to the direction of travel during work and above the ground); PA1 the connecting means connecting the connecting member to the hitching structure includes a journal connected to the connecting member and extending through a guide device connected to the hitching structure; PA1 the guide device includes a slot extending transversely to the direction of travel during work; PA1 the slot is at least substantially rectilinear; PA1 the longitudinal axis of the slot extends at least substantially at right angles to the direction of travel during work and at least substantially horizontally; such a positioning of the slot makes it possible, in the work position, for the connecting member to move transversely to the direction of travel during work and in the transport position prevents said connecting member from moving significantly; PA1 the longitudinal axis of the slot intersects the longitudinal axis of the first articulation; PA1 the longitudinal axis of the slot intersects the longitudinal axis of the first articulation at least substantially at right angles; PA1 the pivoting of the cutting mechanism about the longitudinal axis of the second articulation is limited in each direction by a stop; PA1 the stops are situated close to the connecting means connecting the connecting member to the hitching structure; PA1 the stops are formed by the two ends of the slot; PA1 a lever mechanism is provided, this being situated between the cutting mechanism and the suspension arm, the connecting member being connected to said lever mechanism; PA1 the lever mechanism includes a pivoting lever with two branches: PA1 the lever mechanism additionally includes a link rod situated between the pivoting lever and the cutting mechanism, said link rod being connected on the one hand to the pivoting lever by means of a sixth articulation and on the other hand to the cutting mechanism by means of a seventh articulation, the longitudinal axes of said sixth and seventh articulations being at least substantially parallel to the longitudinal axis of the second articulation; PA1 the seventh articulation is an elastic articulation; PA1 the machine for cutting plants includes a stabilizer device intended to return the cutting mechanism to a predetermined position when said cutting mechanism is in the work position; such a stabilizer device additionally makes it possible, when maneuvering at the end of the field, when the cutting mechanism is suspended transversely to the direction of travel during work above the ground by means of the suspension arm, to keep said cutting mechanism in the predetermined position; PA1 the predetermined position is the normal work position, that is to say the one in which the cutting mechanism extends at least substantially horizontally; PA1 the stabilizer device includes two elastic elements acting in opposite directions; PA1 each elastic element is situated between the connecting member and the suspension arm; PA1 the intensity of the action provided by the stabilizer device is adjustable; PA1 the connecting member extends above the suspension arm; such a position of said connecting member advantageously allows it to be kept away from the plants in order not to compromise the correct operation of the locking device; PA1 the connecting member consists of a rod extending at least substantially parallel to the suspension arm.
2. Discussion of the Background
Such a machine for cutting plants is disclosed in document EP-A-0 655 186.
This known cutting machine, broadly speaking, includes a hitching structure, a cutting mechanism, a suspension arm and a locking device.
The suspension arm is connected to the hitching structure by means of a first articulation of upward-pointing longitudinal axis so that it can be pivoted into a work position and into a transport position about said longitudinal axis.
The suspension arm is also connected to the cutting mechanism by means of a second articulation of substantially horizontal longitudinal axis so that said cutting mechanism can pivot about said longitudinal axis so as to be able to follow the lie of the land during work.
The locking device for its part is intended to lock, in the transport position, the pivoting of the cutting mechanism about the longitudinal axis of the second articulation and to allow said pivoting in the work position. For this, the locking device includes a pivoting plate connected on the one hand to the cutting mechanism by means of an additional articulation of longitudinal axis parallel to the longitudinal axis of the second articulation and, on the other hand, to the suspension arm by means of a connection. This connection is composed of a slot having a first part which is substantially vertical and a second part which is substantially horizontal and at right angles to the first part. This connection additionally includes a guide shaft fixed on the suspension arm, which guide shaft extends into the slot in such a way that in the work position the first part of said slot can move over said guide shaft to allow pivoting of the cutting mechanism about the longitudinal axis of the second articulation.
The locking device is also provided with an actuating means connected on the one hand to the pivoting plate and on the other hand to the hitching structure in such a way that when the suspension arm and the cutting mechanism are pivoted into the transport position about the longitudinal axis of the first articulation, said actuating means acts on the pivoting plate to make it pivot about the longitudinal axis of the additional articulation. For this, the second part of the slot becomes housed over the guide shaft allowing the cutting mechanism to be fixed to the suspension arm.
When the suspension arm and the cutting mechanism are pivoted into the work position, the actuating means stops acting on the pivoting plate, which is returned to its work position where the first part of the slot can move over the guide shaft, by means of an elastic element.
Most of the locking device, especially the pivoting plate and the guide shaft, is situated just above the cutting mechanism, between the latter and the suspension arm.
It is well known by those skilled in the art that the upper part of the cutting mechanism is particularly exposed to the plants, which means that there is a risk of the correct operation of the locking device being compromised.
Furthermore, the means of actuating the locking device of this known cutting machine consists of a string which becomes slack when it stops acting on the pivoting plate in the work position. When the string is slack it dangles down toward the ground along the suspension arm, and risks hampering correct operation. This is because there is a risk of this string becoming caught up in the fodder or in a moving part such as, for example, the wheel of the motor vehicle to which the cutting machine is hitched. In addition, when the cutting machine is transported, the string is subjected to fairly high stresses, especially when the motor vehicle to which the cutting machine is hitched runs over ruts, and there is a risk of said string breaking.
The design of this known locking device is relatively weak, and there is the risk that this will lead to fairly steep costs.